Pneumatic control device having range adjustment



R. C. MOTT March 28, 1961 2,976,877

PNEUMATIC CONTROL DEVICE HAVING RANGE ADJUSTMENT 5 Sheets-Sheet 1 I0 INVENTOR.

RICHARD C. MOTT fi f Filed May 25, 1959 ATTORNEY R. C. MOTT March 28, 1961 PNEUMATIC CONTROL DEVICE HAVING RANGE ADJUSTMENT 5 Sheets-Sheet 2 Filed May 25, 1959 IQ i 38 INVENTOR.

Rich/m0- c; MOTT ATTORNEY March 28, 1961 R. c. MOTT 2,97 ,87

PNEUMATIC CONTROL DEVICE HAVING RANGE ADJUSTMENT Filed May 25, 1959 s Sheets-Sheet 5 ll Ill -8 In] '"""*m|| 7 7 E W I26 QQ-gl HE ES *gggg 92 FiY. 9

INVENTOR.

RICHARD C. MOTT BY 477' R/VEY United States Patent PNEUMATIC CONTROL DEYICE D USIWN g ssignor to Min- Richard C. Mott, Harwood Heights, 11]., Minneapolis,

nafiblis-Ho'rieyjvell Regul tor" Company,

Filed May 25, 1959, Ser. No. TClaims. ((21. 137-85 Device, Serial No. 690,717; 'file'd 'October 1 7;1951, now

Patent 2,937,655, issued Mayan, raha' whieh discloses 7 a pneurnatic controld'e'vic or relay' having range adjustment and overwhichthis'applicatiori is an improvement In that applicatio'n, range adjustment of a pneumatic contr' ol 'devic isefiected by change in" the effective areabf the pilot diaphrag m through'afclamping means associated therewith. lli the present" invention "the "same tjyp'e' of Eeh e' adjustment'is utilized in a "pneumatic control devipfe b an improvementih diaphragm'shape andclamping means permits a'sirnplificatioii (fever-e11 desig'nanida greater range of adjustrnentl' 'Tlie' objector thi's'invention is toprovid e a simplified range adjustment i-nIa'pneu -matic control device with a considerably reater ang nt adjustment and ease in adjustment. It also providesa' structure whichis 'ea sy'to rnai rid economical to manufacture. These *ahd" other" ob 6f t e' ihvehtiehwi11 he o te a arent frond '5 read of the a'tta c heddeshriptlion toiiie'fwit he drawings" whereim Figure 1 i' 'e ahvrew are regulatingd evice with a coye'r r 1 Figure 2" is a side elevation'vi w in irregular section taii en' along the lines fln' Figure l tosl'iovii the" "meta V s. 1., *"h I v- -L,-

Figures 3, 4, 5, and 6 are elevation views of a portion of'tiie 'pneun iatic control"device showing' the range adjnstir ient mechanism in'v-ar'iollsistag's orYangesQfid stf rm. V, r "Figure 7 is a bottom view of a portion of the pneumatic control device dis closing a pneumatic relay, Figiire8 is a sectional viw o fthe portion of the apparatus howh in Fig u fe l flb ng thediijs S l s; iid Figure 9"is a 5% dual View of a follower "s'p ifg incorporatedin the pneumatic controldei/ic' YfVanaf A mlll'El-Pfllfhbll mg or cas1n ructure 1ncludi {a baise"1 0,ari intermediate securing r1ng"11 and sea portion 12 iakedip ah e'nclosirigcasirig' for'th'e contfoldevi'ce in which tli ba e section 10 Bas a" plurality crimes 14 and" ISIeprsent in'g the inlet supply aha pilot pressure orts for the devicel BasQS'truc't'iir 10 ha's a eneiial recess 20 therein in whic h is' positioned a"'r"e'1ay housing block 21 restsoh' an ar'iri'ularrid'g'e poi- "tram; of the ba'sein recss'ZQ and'has a sfiitablesealing means or gasket 24"position ed therebtweeni The relay 2 sealing purposes. A similar lip or beaded'inner periphery isl'ifiic'ludedfifi the' diaphrlagni'which is positioned "'ir'ia c 'r necting iner'iiber'QSF Member 35' has e" central-1y lbcatedi'threadjd recess' 36 therein in which is'positioned ESCTEW i flinbfli having it WaSileI DI positioning'me'ans 39 positioned 'abg'veth'e same to 'hold the inner bead of theditiphraglnfin place on'rnernber 35 sealing the same and defining the pilotichamber 26. The outer periphery fthe diaphragm' 3'0 is held inposition on the relay block 2 byfineansbf an annular retainer member 40* whose "titer periphery" overlies the outer periphery of the dia phragrrfa nd" which includes a plurality of inwardly projecting flanges 42' for purposes of which will be later notedi Thefannulaf' rne'rhber'40 is heldin position against th block 21159 "iriaiisof the cylindrical support member ll'iivliiiclfis 'threadedatits outer periphery into the casing partm' and mounts l'so o'n'its outer periphery the cover irimber" 12'. "Cover rr'irnb'enlzbas a'centrally located aperture'thereini1i"which an adjusting screw is posit'io idi the ser w' mounting at 'i t's extremity a spring retainer 5 1within the'6onfinesof the casin'g which holds the end '61: the'staft spr iiigifg for the device whose oppositeeirtjrerii i'ty is'positioii'ed in a recess in the connecting her 351"" Il econnectirig irnernber' 35 also has a phidf lingers 6r 'fla'nge's" which are positioned above 'ii'f riii'gs'"56, "5;7'res'ting' in'the convolutions'pf phra'gtn'Whi'eh op rate" as"u lti'm'ate limit stops n "asthy ave upward'inaananner to be d. "Connecting member 35 'also" has an ahhin grflah section"" adapted to engage the projectiqns or nah e s'flZ" on the support member 40 as will be Sieh in F ig e 2. Eachflan'ge" 42' carries a pair of screws 6, 67 whichf'coopi'at with the rings'56j57 respectively aha ere hd usttihie within the respective flanges 42' to liin t th 6v ent of" the res ective rih s a d efre'cra change in effective" area'bf 'the diaphragm for the pilot chamber 2616" vary the range adjustment or rangeof operati 'dn of the device. Start adjustment for the contrerdgvi'cejs 'bbtai ihd'by adjusting attaining the cover the th aded'securihg ring 11 which urges the spring s'iipport'51"and the spring thereon in a direction to'feithe'r increas'e ot'deerease the spring tension onthe conncting' rne iiiberias aud'hence the diaphragm 30; The headedscrewnieans '50 merely serves to hold a supporting platesl' in pos tion. screw means 38 which is threaded into a connecting Tater "dsc t member 35'to securdtlfe diaphragm thereto also has a block has'ia central aperture #25 thereth'r'ough and its 1 upper surface 'is recessed as at to define part of a pilot chamber to .be later described. Positioned above the relay block 21 is'an ,annular ,convoluted'diaphragm .30 having a .lip ,or ebead portion .31 at ,the outer periphery whi h sets into a .notched recess ,in the relavblqck to:

1 ins ;1 g k th reofi indicated a .90 has .cqn y es ereto tappedaperture'W'into which a'threaded connecting member is threaded or positionedfth'e connecting rriber extending through the aperture 25 in the relay block zranseehtmnhie'etih with the'cha'mber 26. The connecting" member "71' has attached thereto atits lower p'r'iplierya gasket 75 which'is secured through suitable lo'cli niit' rheaii sflifi to a recess in the'base of "the relay block 21 coinnion toth aperture 25,the sealinginember or "gasket 75"'ib e'in g connected to 'the' connecting rnernbero'r rod 7Iby means of "a lock 'nut and Washer indicatedat '80. 'Reciving member 75' seals the chamher at the lower "siirfac'ethereof and the pilot chamber 26 receives an airsupply through "a'passage indicated in phantom "at 82 (Figure 2) leading to the inlet duct orport 15. iAl'so positioned in pilot chamber '26'is'a spring'mefnber or re urn" spring 85 which rests 'at one eitrernity in a spring receiving recess in the upper surface 'of the" block" '21 and against a lower surface of the diaphragm 30 to urgethe diaphragm upward against the tension'spring 535" This spring is included herein for spring balancing purposes and can be omitted if desired; Jhe shaft 71'1connectedto the connecting member 35 moves with moivement ojf ,the ,diaphragnrrelatiye to the casing means and base member 2 a i proi i a further connection member 91 with a link 92 secured thereto through a suitable universal type linkage or joint 93. Positioned between the connecting member 91 and the member 71 is a plate 95 forming a part of the relay mechanism,the specific details of which are shown in detail in the above identified Vana patent and the F. D. Joesting Patent No. 2,310,293, dated February 9, 1943 and are described briefly below. The relay mechanism, shown in part in Figures 2, 7 and 8, be three-way valving unit. It includes a pair of ball'valve members 100, 104 held in recesses in the relay block 21 which are connected to ports or conduits 102, 106, as will be later identified. The respective ball closure members 100, 104 are urged away from their respective ports 102, 106 or conduits to open the passages through springs 103, 105 respectively. The ball valve members and the respec-' tive conduits or ports provide the two valve members making up the three-way valve configuration, one of which is an inlet valve (100, 102) and one of which is an exhaust valve (104, 106). Air flow in the recesses around the ball valve members which seat on the ends of their respective conduits is facilitated by grooves or slots 112 in the recesses such as is shown in phantom in Figure 7. Plate 95 of the relay mechanism has the link 90 projecting through it and is positioned between the nut and washer assembly 80 and the connecting member 91. The spacing between the nut and member 90, which is shown exaggerated in Figures 2 and 8, is such that the plate will be engaged and tilted, as will be later seen, with slight upward or downward movement of the member 90 from a reference position in which both valve members are closed. As will be seen in Figures 2, 7, and 8, the plate rests against and holds the ball members 100, 104 in their respective recesses in block 21. A spring 107, positioned in a recess 108 in block 21, also bears against plate 95 and stop or guide pins 109, 111 threaded into block 21 position the plate laterally with respect to the ball valve members (see Figure 7). The spring 107 and pins 109, 111 urge the plate 95 against the ball members and the plate pivots or tilts with upward or downward movement of the pin 90 about axes extending between the spring and the respective ball valve members 100, 104. Thus, upon tilt of the plate 95 with upward or downward movement of the linkages 71, 90 and 91 through diaphragm movement one or the other of the valving members will become unseated to open the respective passage while the plate tilts on the other.

extremity which is adapted to ride against or with the movable element (not shown) of the device to which control air is supplied by the pneumatic relay. A second spring 124 is positioned between the plate 121 and a wall 126 of the device to urge the plate against the movable element. Thus the follower spring will have its extremity positioned with movement of the device to be controlled and will apply a variable bias on the pilot diaphragm 30 in a conventional follow-up manner to act against the signal or branch pressure supplied to the chamber 26. The air supplied both to the pilot port 14 and to the branch or signal port 15 is filtered through filters such as is indicated at 125 in Figure 2 at the entrance of ports 14, 15.

Figures 3, 4, 5, and 6 show various operating conditions for the range adjustment mechanism of the control device. A control apparatus in general operates in the same manner as that disclosed in the copending Vana As indicated in Figure 2, the passage 102 leads to the 1 chamber 20 which is vented to atmosphere through means or a conduit (not shown). Similarlythe second valving member 104 is connected from the supply port 14 through a conduit shown at 106, in Figure 8, to the valving member 104 from which air enters the chamber formed below the relay block 21 and defined by the gaskets 24 and sealing member 75 to be exhausted through an aperture indicated at 110' in the base member 10 (see Figure 2). This is the output port of the valving arrangement and supply air is modulated or controlled by movement of the plate 95 to pass through the passage 110 and to the device to be operated thereby. Air from the operating chamber of the device to be operated is exhausted through the valve formed by the valve member 100 and conduit 102 to atmosphere with the opening of the valve and the closure of the valve formed by the ball valve member 104 and conduit 106. A supporting plate 120 is shown connected through seal means 121 to the base member 10. The aperture 110 is actually defined by sleeve member 122 having a threaded outer periphery by means of which this control device is connected tothe device to be operated and through which the outlet air is supplied to such a device (not shown). Connected to the link 92 in passage 100 of sleeve 122 and normally positioned inthe operating chamber of the device to' be operated or controlledtnot shown) is a follower spring 120-.- Spring 1-20-has-a plate 121 connected to its opposite application in that pilot pressures applied to the pilot chamber will displace the pilot diaphragm and hence the connecting member against the start spring which is also adjustable to determine the pressure at which it starts to move. Movement of the diaphragm and hence the connecting member will move the linkage to tilt the movable member of the valve mechanism to selectively open and close the inlet and exhaust ports leading to the outlet chamber of the device. Start adjustment for the relay mechanism herein is accomplished by displacing the cover relative to a calibrated indicia (not shown), normally included on the base member 10 on the outer periphery thereof to selectively position the end of the start spring 53 and vary the pressure or spring tension applied to the diaphragm. Movement of the plate of the valving mechanism about a pivot point (not shown) Will cause one of the ball valve members to be lifted from its a seat While the other is secured thereto. Displacement of the opposite direction will seal the first named ball valve member and open the second to provide the desired valving operation which is conventional. Output air is fed through the passage to the device to be operated (not shown) and the connecting member 92 is adapted to be connected to a follower spring to provide a followup action on the diaphragm. Range adjustment is provided simply herein through the use of the annular rings positioned in the dwell portions of the convoluted dia phragm over which are positioned the adjusting screw members 66, 67.

In Figures 3, 4, 5, and 6 are shown respectively the various range adjustments available with this apparatus, Figure 3 showing the highest range, the Figure 4 the second highest range, Figure 5 the lowest range and Figure 6 the third highest range of adjustment. It will be noted in Figure 3 that the screws 66, 67 are adjusted inwardly in the flange sections 42 and the rings 56, 57 are restrained so that most of the diaphragm will not leave its conventional or normal position and only that portion of the diaphragm adjacent the connecting memher will be free to move with pressure change in the pilot chamber 26. The effective area of this chamber is determined by the mean diameter of this innermost convolution. The second highest range is shown in Figure 4 where the screws 66 are threaded into the flange section 42 to restrain the respective ring 56 while the screws 67 are withdrawn permitting the two innermost convolutions to be free to move and allowing the ring 57 to ride against the stop members 55 in the uppermost position to apply a force to the connecting member and hence' the associated linkage. Similarly in Figure 5, both screw means are withdrawn and the rings 56, 57 are free to move with movement of the diaphragm to provide the lowest pressure range adjustment for the device. Figure 6 shows the second intermediate range somewhat lower than that of Figure 4 and in which the screw 67 is ad-' vanced to restrain the movement of the ring 57 so that the diaphragm will move at the outer two 'convolutions as well as inner convolution adjacent the connecting member. It will be noted that in the uppermost posh tion the outer'ring 56 will ride against ,the'stop .55. .Ultir mate movementof the connecting .inember is fixedby engagement of the stop portion 61) with the flange sec.- t'ions 42 as shown in the sketches.

This shape and arrangement of parts provides a.simplified adjustment mechanism which does not. require re.- moval of any parts, any accurate machining and 1308i:- tively limits .the displacement of the diaphragm withvadjustment of the screws. It fnrther provides a wider variation of range of adjustment with an apparatus'which is economical to manufacture and maintain. In consider.- ing this invention 'it should be remembered thatv the present disclosure is intended ,to she illustrative only-and the scope .of the invention should .be determined only by the appended claims.

I claim:

1. A pneumatic relay comprising a casing having it recess therein, an annular convoluted diaphragm positioned in said recess and attached at its outer periphery to said casin-gto define a pilot chamber therein which is variable in volume, inlet means extending through said casing to said chamber to provide av passage for'control air pressure thereto, means conne ted iOihe n e P r riphery of said convoluted diaphragm to seal said chimber, valve means mounted on said casing remote from said chamber and having movable means to sequentially pe and cl se a pair of va ving mem e s co nect d to supply, outl t and exhaust pass ges pos tioned said casing, means connecting said means on said diaphragm to Said notab e ,valreaz aa t9 oreate aid valv means with movement of sa'id'dia'phragm, a plurality bf concentric rings positioned in said cent/murmur of said diah asmtflaase ne w sst t a sahq s a diap ra m adjustment grai s res n, 22 flange means and overlying said plurality of rings being'adapted to be positioned against said rings to restrain movement of portions of said diaphragms wherein said rings are positioned, and biasing means bearing against a portion of said casing and resting against a diaphragm means to urge said diaphragm towards said pilot chamber.

2. A pneumatic relay comprising a casing having a recess therein, a convoluted diaphragm positioned in said recess and attached at its outer periphery to said casing to define a chamber therein variable in volume, inlet means extending through said casing to said chamber to provide a passage for control air pressure thereto, operating means attached to said diaphragm at the inner periphery thereof and forming a seal therebetween having a flange portion extending through said chamber, valve means mounted on said casing remote from said chamber and having movable means to sequentially open and close a pair of valving members connected to supply, outlet and exhaust passages in said casing, means connecting said operating means of said diaphragm to said movable valve means and including means for sealing said chamber remote from said diaphragm, said connecting means being operable to move with movement of said diaphragm to operate said movable valve means, a plurality of concentric rings positioned in the convolutions of said diaphragm, flange means connected to said casing above said diaphragm, and adjustable screw means positioned in said flange means overlying said concentric rings and adapted to be threaded through said flange means toward and away from said rings; said screw means when engaging said rings preventing movement of portions of said diaphragm from a normal position, and biasing means bearing against a portion of said casing and resting against said operating means of said diaphragm to urge said diaphragm towards said chamber.

3. A pneumatic relay comprising a casing having a recess therein, a convoluted diaphragm positioned in said recess and attached at its outer periphery to said casing to define a chamber therein variable in volume, inlet amass meansextending through said casing to said chgmber to provide a passage for control airpressnre {there ating means attached to. .Sai diaphragm .84 I1 niphery thereof .and forming a seal therebetween flange portion extending through said chamber, Q means mounted on said casing remote from said hanther and having movable means to sequentially open close apair of valving membersconnected supply, o t, let and exhaust passages in said casing, means connect ng said operating means of said diaphragm to said movable valve means and including means for scalling-saidchember remote from said diaphragm, said connecting means being operable to move with movement of said diaphragm to operate said movable valvermeans, a plp rality of concentric rings positioned in the convolutionsofsaid diaphragm, flange means conneqt d to Said cas g a ov said diaphragm, and adjustable screw means positioned in said flange means overlying said Concentric rings and adapted to be threadedthrough aid fl g ans oned and .awayfrom said rings, said screw means when engaging said rings preventing movement of portions of said diaphragmfrom anormal position, stop means included in said operating means of said diaphragm and overlying said plurality .of rings to define aflxediposition of movement of said diaphragm independent of said screw means, and biasing means bearing againsta portion of said casing and resting against said operating means of said diaphragm to urge said diaphragm towards said chamber. 4. A pneumatic relay comprising a casing having a recess therein, a convoluted diaphragm positionedin said recess and attached at its outer periphery to .said casing to define .a chamber therein variable in volume, inlet means extending through saidvcasing to said chamber to provide apassage for .control air pressurethereto, operating nteansattached to said diaphragm at the inner periphery thereof and forming a .s'eal therebetween having-g1 flange lp'ortion'extending through said chamber, valve means mounted on said casing remote from said chambet and having movable means to sequentially open and close a pair of valving members connected to supply, outlet and exhaust passages in said casing, means connecting said operating means of said diaphragm to said movable valve means and including means for sealing said chamber remote from said diaphragm, said connecting means being operable to move with movement of said diaphragm to operate said movable valve means, a plurality of concentric rings positioned in the convolutions of said diaphragm, flange means connected to said casing above said diaphragm, and adjustable screw means positioned in said flange means overlying said concentric rings andadapted to be threaded through said flange means toward and away from said rings, said screw means when engaging said rings preventing movement of portions of said diaphragm from a normal position, stop means included in said connecting means of said diaphragrn and overlying said plurality of rings to define a fixed position of movement of said diaphragm independent of said screw means, cover means threaded to said casing and adapted to be adjustably positioned thereon,

and spring means positioned between said cover means chamber to provide a passage for control air pressure thereto, means connected to the inner periphery of said diaphragm means to seal said chamber, valve means included in said casing means and having a pair of valving members controlling inlet, outlet and exhaust passages, conduit means connecting said passages in said casing means to supply, exhaust and outlet ports, said valve ing and said diaphragm and being adjustable to vary the spring tension on said diaphragm to afiect start adjustment of said relay.

6. A pneumatic relay comprising, a casing means having a recess therein, convoluted diaphragm means positioned over said recess and attached at its outer periphery thereto to define a pilot chamber variable in volume, inlet means extending through said casing means to said chamber to provide a passage for control air pressure thereto, means connected to the inner periphery of said diaphragm means to seal said chamber, valve means included in said casing means and having a pair of valving members controlling inlet, outlet and exhaust passages, conduit means connecting said passages in saidcasing means to supply, exhaust and outlet ports, said valve means including a movable member for selectively operating said valving members, means connecting said movable member on said valve means to said means on said diaphragm, sealing means included in said connection means to seal said chamber, range adjustment means for said relay including adjustable stop means positioned in part on said convoluted diaphragm and in part on said casing means and adapted to selectively restrict movement of portions of said diaphragm to aflect range adjustment thereof, start adjustment means including an adjustable spring means connected between said casing and" said diaphragm and being adjustable to vary the spring tension, on said diaphragm to afiect start adjustment of said relay, and means connected in part to said diaphragm connection means for limting movement of said diaphragm independent of said rangeadjustment means.

- 7. A pneumatic relay comprising, a casing means having a recess therein, convoluted diaphragm means positioned over said recess and attached at its outer periphery thereto to define a pilot chamber variable in volume, inlet means extending through said casing means to said chamber to provide a passage for control air pressure thereto, means connected to the inner periphery of said diaphragm means to seal said chamber, valvemeans included in said casing means and having a pair of valving members controlling inlet, outlet and exhaust passages, conduit means connecting said passages in said casing means to supply, exhaust and outlet ports, said valve means including a movable member for selectively operating said valving members, means connecting said movable member on said valve means to said means on said diaphragm, sealing means included in said connection means to seal said chamber, range adjustment means for said relay including adjustable stop means comprising a plurality of rings positioned in the convolutions of said. diaphragms and adjustable stop means mounted on said casing means, and start adjustment means including an adjustable spring means connected between said casing and said diaphragm and being adjustable to vary the spring tension on said diaphragm to afiect start adjustment osaid relay.

References Cited in the file of this patent UNITED STATES PATENTS Maliplant Mar; 26, 1940 2,811,138 Clements Oct. 29, 1957 

